Mechanical double-action press of link mechanism type

ABSTRACT

Mechanical double-action press of link mechanism type, in which metal sheet blanks are produced to formed articles by a drawing work, and in particular, within the pressing region, the speed of an inner slide is remarkably slow thereby to produce no cracking or cutting, and at the ascending and returning period of the inner slide, said inner slide is accelerated and rapidly ascends, whereby it is intended to increase the production efficiency of the press-formed articles having no cracks or cuts.

United States Patent Kita A [54] MECHANICAL DOUBLE-ACTION PRESS 0F LINK MECHANISM TYPE [72] Inventor: Masaaki Kita, Komatsu, Japan [73] Assignee: Kabushiki Kaisha Komatsu Seisaku'sho, Tokyo-to, Japan [22] Filed:

Aug. 14, 1970 [21] Appl. No.: 63,735

[52] US. Cl. ..'....72/450, 100/237, 100/282 [51] Int. Cl. ....B2lj 9/18 [58]- Field of Search ..72/450, 452, 449, 451, 400, 72/403; 100/237, 282

[561 References Cited UNITED STATES PATENTS 3,130,699 4/1964 Ward ..72/450 2,550,064 4/1951 Ward ..72/450 3,052,200 9/1962 Dehn 100/282 51 Oct. 3, 1972 FOREIGN PATENTS OR APPLICATIONS 587,093 l-l/l959 Canada ..72/450 839,456 l/l939 France; ..72/450 Primary Examiner-Charles W. Lanham Assistant Examiner-Gene P. Crosby Attorney-McGlcw and Toren [5 7] ABSTRACT Mechanical double-action press of link mechanism type, in which metal sheet blanks arev produced to formed articles by a drawing work, and in particular, within the pressing region, the speed of an inner slide is remarkably slow thereby to produce no cracking or cutting, and at the ascending and returning period of the inner slide, said inner slide is accelerated and rapidly ascends, whereby it is intended to increase the production efficiency of the press-formed articles having no cracks or cuts.

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MECHANICAL DOUBLE-ACTION PRESS OF LINK Y MECHANISM TYPE I BACKGROUND OF THE INVENTION The present invention relates to a mechanical double-action press of link mechanism type. I

In general,- a mechanical double-action press is operated by driving its inner slide by means of simple crank mechanism.

In drawing works of metal sheets, the maximum drawing speed is limited to a specified certain value for respective sheet material. In press works, however, the drawing speed becomes equal to the pressing speed of the slide, so that when the slide speed exceeds the limit speed of the material, cracks and cuts are produced in I being accompanied with the above disadvantage, it is preferable not to resort to the conventional driving mechanism in which the motion depicts a sinusoidal diagram, but to utilize an interlocking mechanism which makes the slide speed at the pressing region remarkably slower than in the case of sinusoidal diagram motion and which accelerates said slide speed at idling stroke.

A number of single-action presses having the abovementioned interlocking mechanism kind have been practised up to now, but it was impossible to adopt the interlocking mechanism employed in the single-action presses to double-action presses on the construction. Accordingly, it has been earnestly desired to develop the interlocking mechanism in the double-action press having the above-mentioned characteristic features.

BRIEF SUMMARY OF THE INVENTION The present invention is to provide a mechanical double action press of link mechanism type.

An object of the present invention is to make the velocity at the time of the idle stroke namely approching stroke and return stroke higher than the velocity at the time of the drawing stroke thereby to shorten the time to be required in one cycle. Whereby the productivity is intended to increase.

Another object of the present invention is to provide a mechanical double-action press making the operation such that a relatively long time to be taken to an ascending stroke is distributed to the working stroke thereby to reduce the drawing speed of the inner slide in the range of press cycle and even if the drawing speed is depressed less than the limit speed, it is possible to increase the stroke number per unit of time of the press.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional elevation view showing each half of driving mechanism of inner and outer slides of a mechanical double action press which shows one embodiment of the present invention;

FIG. 2 is anenlarged sectional view, in which a left half portion and a right half portion are respectively corresponding to lines 1-1 and II-II in FIG. 1;

FIG. 3 is an enlarged sectional view taken along the line III-III of FIG. 1;

FIG. 4 is an enlarged sectional view taken along the line IV-IV of FIG. 1;

FIG. 5 is an enlarged sectional view taken along the line V-V of FIG. 2, showing the outer slide driving mechanism;

FIG. 6 is an enlarged sectional view taken along the line VI-VI of FIG. 2, showing the inner slide driving mechanism;

FIG. 7 is a curve showing the motion of they inner slide and the motion of the outer slide of the press of the present invention.

DETAILED DESCRIPTION The present invention will hereinafter be described with respect to an example referring to the drawings.

Referring to FIGS. 1 through 4, a pair of main shafts 3, and 3 which are arranged coaxially with their end faces spaced at a slight distance are provided on the right-hand of a crown 2 at the upper portion of the body 1. Similarly, a pair of main shafts 3 and 3 which are arranged coaxially with their end faces spaced at a slight distance are provided on the left-hand of the crown 2 at the upper portion of the body 1. A drive gear 4 is fixed to each of the main shafts 3 3 3 and 3 An electric motor 5 is mounted on the crown 2 and byoperating said motor 5, a flywheel 7 can be rotated through a belt 6 and is adapted to be clutched with a drive shaft 8 by a clutch means (not shown). A gear 9 fixed to the drive shaft 8 is engaged with an inter mediate gear 12 which is fixed to a shaft 11 supported by a bearing 10. Said shaft 11 extends from the front toward the rear of the crown 2 on its right hand. A pinion gear 13 is fixed to the shaft 11 at a predetermined distance. The intermediate gear 12 is engaged with another intermediate gear 12 which is fixed to, another shaft 11 supported by another bearing 10. Another shaft 11 extends from the front toward the rear of the crown-2 on its left hand. A pinion gear 13 is fixed to another shaft 11 at a predetermined distance. Each shaftll is adapted to be rotated by a different one of the intermediate gears 12, one of which is rotated by the gear 9 of the drive shaft 8 by clutchsetting. The drive gears 4, 4 fixed to main shafts 3 and 3 are respectively engaged with said pinions 13, 13 fixed to the shaft 11. The drive gears 4, 4 fixed to said main shafts 3 and 3., are respectively engaged with said pinions 13, 13 fixed-to the other shaft 11.

A eccentric portion 14 is projectingly provided on the end surface of each of said drive gears 4, and the center of each eccentric shaft portion 14 is eccentric to the center of each drive gear 4 at a predetermined distance.

An inner slide driving rod is fitted on each of the eccentric shaft portion 14. A projecting portion is provided on each of the upper portions of the rods 15 and also is positioned above the place where the'main shafts 3,, 3,,3 and 3, are fitted in each of rods 15. A pin 17 is provided on the projecting portion 16 of each of the rods 15, and the center of said pin 17 is eccentric from each center of the main shafts 3,, 3,, 3 and 3,, at a predetermined distance. One end of each link member 18 is pivoted to each pin 17 and the other end of said link member 18 is fitted to an outer slide driving shaft 19.

The outer slide driving shaft 19 extends from the front toward the rear of the crown 2 on its right hand. Similarly, one end of the link member 18 is pivoted to each pin 17 and the other end of said link member 18 is fitted to-another outer slide driving shaft 19 which extend from the front toward the rear of the crown 2 on its left hand.

The upper end of each first connecting member 20 is pivoted to the lower end of each of said inner slide driving rod 15, and the lower end of each connecting member 20 is pivoted to the upper portion of an inner slide 21.

A plate 23 is provided integrally on each drive gear 4, so that each eccentric shaft portion 14 may be positioned between said plate 23 and the main body of each drive gear4. The center of each pin 22 provided on the plate 23 has a predetermined distance from the center of each eccentric shaft portion 14'. One end of each connecting lever 24 is pivoted to one of'the pins 22 and theother end of each connecting lever 24 is pivoted to the free endof a first swing lever 25 for driving the outer slide 33 by a pin 26. The base portion of each swing lever 25 is fixed on one of the outer slide driving shafts 19. The base portion of each second swing lever tion of one of the connection levers 31 by a pin 30. The

.- pin 30 in the outer slide driving lever 28 is positioned upwardly from the pivoting point of the main shaft 3 3,, 3 and 3 and each outer slide driving lever 28 corresponding thereto.

The upper end of each second connecting member 32 is pivoted on the lower end of one of the outer slide driving levers 28, and the lower end of each connecting member 32 is pivoted to the upper portion of an outer slide 33'. In FIG. 1, number 34 is a bolster and number 35 is a bed. In FIGS. 3 and 4, number 36 is a tie rod.

The present invention will be operated as described hereunder.

The flywheel 7 is rotated by means of a belt 6 by operating the motor 5, and when the clutch sets, the drive shaft 8 is rotated and then the intermediate gear 12 is rotated by the gear 9 thereby to rotate the shaft 11. The drive gears 4, 4 engaging with said pinions 13,

, l3 fixed 'to said shaft "11 are rotated in an arrow direction, whereby the torque is distributed into the front and rear directions. Another intermediate gear 12 is rotated by the intermediate gear 12 thereby to rotate moves upwardly and downwardly. Since the motion is restricted by the link member 18 pivoted to the projecting portion 16 at the upper end by the pin 17, the route of the connecting point P at which the lower end of the rod 15 is connected to the connecting member 20 generates an ellipse-like cycle as shown by a chain line in FIG. 6.

Thus, the inner slide 21 descends with substantially V uniform speed in the drawing area, and as shown in the upper half portion of the route, after pressing the blank material by an upperdie mounted on the'lower side of the inner slide at the final position, at the portion where the direction of the route is changed, said inner slide 21 is accelerated in the idle stroke and ascends rapidly. In

such a manner as described above, the inner slide 21 is moved upwardly and downwardly by means of the connecting member 20.

On the other hand, with the rotation of the drive gear 4, the connecting lever 24 which is pivoted by the pin 22 integral with said drive gear 4 is rotated simultaneously, and the swing lever 25 connected at the top end of the connecting lever 24 is swung upwardly (as shown by a full line), thus the outer slide driving shaft 19 is rotated for a desired angle.

The swing lever 27. for sliding the outer slide 33 is rotated upwardly in the drawing operation (as shown in the drawing) by swinging the outer slide drive shaft 19, and with this movement, the outer slide driving lever 28 is rotated in a arrow direction through the connecting lever 31 thus pressing the connecting member 32 downwardly and causes the outer slide 33 to descend.

Immediately after one rotation of the drive gear 4 is made, the connecting lever 24 returns to its original position and thus the swing lever ;25 is swung downwardly. By this motion, the swing lever 25 for driving the outer slide 33 also returns'to its original position, and the outer slide driving lever 28 rotates to return, and then the connecting member 32 is drawn up and returns to its original position through the connecting lever 31 and the swing lever 27 In such a manner as described above, the outer slide 33 is moved upwardly and downwardly by means of the connecting member 32.

The curve of motions of the inner slide 21 and the outer slide 33 is shown in FIG. 7, in which their motions are taken as one stroke and abscissa represents time and ordinate represents the upper and lower strokes. As will be noted from the motion curve in FIG. 7, the inner slide 21 is moved showing the slow descending cur\/e in the descending drawing area and also is moved showing the sharp curve in the ascending and returning area. In the motion of the outer slide 33, the curve of from the descending to the drawing area is symmetrical with the curve of from the ascending to the returning.

The stop period of the outer slide 33 at the lower dead point can be set at a desired value by regulating the length of the connecting lever 31 properly.

Thus, according to the present invention, the operating process of the inner slide is not sinusoidal, but within the pressing region, the speed is remarkably slower than in the case where the sinusoidal process is effected, and at the'ascending and returning period after blanks are formed into a predetermined shape the inner slide is accelerated and its returning is effected in a short time. Therefore, no damage such as cracking or cutting is produced. in the formed articles obtained, without the necessity of lowering the number of strokes for the press,.which is very effective for increasing the operational efficiency.

Furthermore, the construction is so simple and the operation so accurate that the device according to the present invention has really an excellent effect as a mechanical double-action press of this kind.

I claim: r v

l. A mechanical double-action press of the link mechanism type, comprising a plurality of main shafts arranged to be driven by a prime mover through a transmission mechanism, adrive gear mounted on each of said main shafts, an eccentric shaft portion provided on each of said drive gears, an upwardly extending inner slide driving rod mounted on each of said eccenof said inner slide driving rods to a corresponding one of said outer slide driving lever shafts, a first swing lever fixed on each of said outer slide driving lever shafts, a pin integrally formed on each said drive gear, a plurality of first connecting levers each mounted'at one end on one of said pins and at its other end to one of said first swing levers, said first connecting levers arranged for swinging said outer slide driving lever shaft for a predetermined angle, an upwardly extending outer slide driving lever fitted on each of said main shafts,'a second swing lever fixed on each of said outer slide driving lever shafts, and a second connecting lever connecting the upper end of each said outer slide driving lever to a corresponding one of said second swing levers fixed to one of said outer slide driving lever shafts.

2. A mechanicaldouble-action press, as set forth in claim 1, wherein a crown encloses said main shafts and is divided into a right-hand side and a left-hand side, one pair of main shafts disposed in axial alignment with the adjacent end faces thereof spaced a slight distance apart in the right-hand side of said crown, and another pair of said main shafts disposed in axial alignment with the adjacent end faces thereof spaced a slight distance apart in the left-hand side of said crown. 

1. A mechanical double-action press of the link mechanism type, comprising a plurality of main shafts arranged to be driven by a prime mover through a transmission mechanism, a drive gear mounted on each of said main shafts, an eccentric shaft portion provided on each of said drive gears, an upwardly extending inner slide driving rod mounted on each of said eccentric shaft portions, a plurality of outer slide driving lever shafts each spaced laterally from one of said main shafts, a link member connecting the upper end of each of said inner slide driving rods to a corresponding one of said outer slide driving lever shafts, a first swing lever fixed on each of said outer slide driving lever shafts, a pin integrally formed on each said drive gear, a plurality of first connecting levers each mounted at one end on one of said pins and at its other end to one of said first swing levers, said first connecting levers arranged for swinging said outer slide driving lever shaft for a predetermined angle, an upwardly extending outer slide driving lever fitted on each of said main shafts, a second swing lever fixed on each of said outer slide driving lever shafts, and a second connecting lever connecting the upper end of each said outer slide driving lever to a correSponding one of said second swing levers fixed to one of said outer slide driving lever shafts.
 2. A mechanical double-action press, as set forth in claim 1, wherein a crown encloses said main shafts and is divided into a right-hand side and a left-hand side, one pair of main shafts disposed in axial alignment with the adjacent end faces thereof spaced a slight distance apart in the right-hand side of said crown, and another pair of said main shafts disposed in axial alignment with the adjacent end faces thereof spaced a slight distance apart in the left-hand side of said crown. 